Since it has been repeatedly stated in the preceding pages that, in every case of fever, the brain, the lungs, and the abdomen are diseased, it may appear objectionable to call any particular class of cases mixed, because, according to the very nature of fever, all must be of this character. But for the same reason that we have designated one class of cases cerebral, another thoracic, and a third abdominal, namely, to mark prominence and intensity of affection, it is right to distinguish a fourth, in which all the three systems of organs are simultaneously affected with an equal, or nearly an equal degree of intensity. The term mixed is therefore by no means employed to intimate that the cases not comprehended under it are unmixed, but merely to point out a fact of great practical importance, that cases do occur which are neither in an exquisite degree cerebral, nor thoracic, nor abdominal, but which, at one and the same time, afford the most exquisite specimens of all the three. From this account of the sense in which the term is employed, it must be obvious that it will include the severest cases that can occur. If a patient be affected with intense cerebral disease he may be in great danger; but if he be affected with an equally intense thoracic disease his danger must be doubled: and if to this be added an equally intense abdominal disease it must be trebled. And accordingly these are just the cases which bid defiance to the most skilful and vigorous measures which the medical art can employ to control them; which seize upon their victim with a force which no human agency can resist nor counteract; which in malignant epidemics destroy life in a few hours or in a single hour, and in ordinary seasons in a few days.